E/VC/VL三元共聚物对水泥砂浆孔结构和性能的影响

Effects of Ethylene/Vinyl Chloride/Vinyl Laurate Redispersible Terpolymer on Pore Structure and Properties of Cement Mortar

利用压汞法和环境扫描电子显微镜分析方法,研究了乙烯/氯乙烯/月桂酸乙烯酯(E/VC/VL)三元共聚物对水泥砂浆孔结构的影响规律,并探讨了其与水泥砂浆的体积密度、抗压强度、抗水渗性、吸水量和吸水率等宏观性能的关系.研究表明:E/VC/VL三元共聚物能显著影响水泥砂浆的孔结构,增大水泥砂浆的孔隙率、总孔体积和平均孔半径;导致大毛细孔显著增多,且密布在C-S-H凝胶之间.E/VC/VL三元共聚物掺量越大,对水泥砂浆孔结构的影响越显著.E/VC/VL三元共聚物改性水泥砂浆的孔隙率和孔体积与宏观性能之间存在密切关系:孔隙率和孔体积越大,水泥砂浆的体积密度和抗压强度越小,但其抗水分渗透性能则越好.

Effects of ethylene/vinyl chloride/vinyl laurate redispersible terpolymer（E/VC/VL） on the pore structure of cement mortar were studied through mercury intrusion porosimeter（MIP） and environmental scanning electron microscopy（ESEM）. The relationships between the pore structure and the properties of cement mortar were also discussed. The results show that E/VC/VL remarkably affects the pore structure of cement mortar. E/VC/VL definitely increases the total pore volume, porosity and the average pore radi- us. E/VC/VL significantly increases the content of large capillary pores of cement mortar, which distrib- ute in the C-S-H gel. With the increase of its use level, the effect of E/VC/VL on the pore structure of ce- ment mortar is enhanced. As the porosity and the total pore volume of cement mortar modified with E/VC/VL increases, the bulk density and the compressive strength of cement mortar decrease, but the water permeation resistance is greatly enhanced.